Prevent the unexpected deallocation of a page table page while performing

pmap_copy().  This entails additional locking in pmap_copy() and the
addition of a "flags" parameter to the page table page allocator for
specifying whether it may sleep when memory is unavailable.  (Already,
pmap_copy() checks the availability of memory, aborting if it is scarce.
In theory, another CPU could, however, allocate memory between
pmap_copy()'s check and the call to the page table page allocator,
causing the current thread to release its locks and sleep.  This change
makes this scenario impossible.)

Reviewed by: tegge@

0 files changed, 0 insertions, 0 deletions